Adding Lightness - gut the fish

Don Plumley · Don Plumley's Garage

Today's project was starting to strip the interior. Here's the result:

And how it starts adding up:

Rear seat backs: 5# each
Rear seat bottoms: 4# each (including some pad)
Rear carpet and pad: 20#
Rear parcel shelf and speakers: 11#
Rear seat belts: 1.5# each
Front seat belts: 2# each

I lost over 55# from my rear today. (Honey, does this make my butt look big?)

Let's say 10# for the RS carpets in the rear area - so a net of #45.

From yesterday's work:

Door Panels: 10# each, net 8# with RS Panels
Seats: 48# each, net 30# with Sparco seats

That's about 120# so far...

sushinav · sushinav's Garage

YES!
AC gone yet?
big battery gone yet?
Steering wheel gone yet?
Spare gone yet?

Don Plumley · Don Plumley's Garage

AC - No, very small weight penaty for drive home cooling.
Big Battery - planned.
Steering Wheel - yes, new Momo Mod 07 ready to install.
Spare - out when I get to the track.

DW SD · 01-19-2006, 06:40 PM

That wil be a fun car! Thanks for the information!
Congrats,
Doug

Don Plumley · Don Plumley's Garage

And 17# for the front carpet/sound deadening...

aigel · aigel's Garage

Well, a nice roll bar or cage will add some more weight back - the diet jojo effect!

George

JohnJL · 01:26 AM

AC is a 60 lb penalty...

livi · 01-20-2006, 01:50 AM

You sure you wanna add any carpeting in the rear ? The bare metal kind of adds a bit of racing look. Cool IMO.

Jeff · 01-20-2006, 06:09 AM

I'm on the same path Don. Looks very familiar. I have a "Modified" muffler and I think one of the best things about this project is how the car sounds on the inside without the sound deadening pads. Very race car like.
I left mine bare metal and have removed the door panels and glass. I will replace it with plexiglass for those cool mornings.
My ride height changed a lot (raised 2-3 inches) after removing the weight, so start looking into new springs if they sren't adjustable on your car.

Have fun and keep us posted on the progress.

Don Plumley · Don Plumley's Garage

Quote:

Originally posted by JohnJL
AC is a 60 lb penalty...

Not in a 933. Much simplier, more compact system. Tyson said 17# if I recall correctly? Anyway, one of my specific reasons for using a 993 platform, instead of an SC tub was working HVAC (plus better brakes, coilovers, and oh yes, a 3.6 in the tail).

Yes, the rollbar does add back in some weight. Hopefully we'll still be at a net loss.

Wavey - I was using a 10# = 1Hp. But as we know, lighter weight have better gains in terms of faster accelleration, deeper braking and less weight for the suspension to handle. Sure would be nice to get under 3000#.

BGCarrera32 · 01-20-2006, 09:17 AM

Quote:

Originally posted by Wavey
120 pounds gone = 18 horsepower added, more or less (according to conventional wisdom).

Dream on...

Bill Verburg · Bill Verburg's Garage

Weight between the wheels, especially when it is low is the least significant kind of weight.

Most of these cars have to run a lot of ballast to make class weight. That's sort of good because the weight is taken from the ends(extremely important) and added low in the middle.

Don if you could, I would love a clean shot of the wiring at the top and passenger side. I can't get at mine till I take the rollbar out.

I am trying to nail down the rear widow and brake light wiring connectors.

makaio · 01-20-2006, 02:23 PM

Quote:

Originally posted by Wavey
What do you think is a reasonable ratio?

I've always heard 15hp for every 100lbs. lost. So I would think your claim would be very close.

As for A/C, I'm with Don. Where we live and the tracks that he's going to, it's not un-common to see 110-115F. in the Summer. So I say unless you're trailering, keep the A/C, no mater what the weight penalty (17 vs. 60lbs.)!

Don, thanks for keeping us posted. Even though I'm not tracking anymore, I'll have to check your car out one of these days when you're at Thunderhill.

Don Plumley · Don Plumley's Garage

Bill - PM me with your email address and I'll post links for the pictures.

Yea, weight behind the rear wheels is best. With the WEVO motor mounts and cat bypass, that will take out about 25#. I'll eventually cut out the sunroof and replace with a CF panel.

Come see it anytime Matt. Maybe in another year or so they'll let me take passengers.

JohnJL · 01-20-2006, 03:00 PM

Wow, 110-115...bad news to be running AC on an aircooled engine in that eat if you get caught in traffic!

jtratza · 01-20-2006, 04:29 PM

The ratio for weight loss to equivalent HP gain dependds on the weight o the car that is a heavier car like the 993 benefits slightly more than a lighter car like an SC or Carrera. Or at least that's what my math is telling me. A 2,756 lb Carrera with 217 hp stock has a weight to hp rating of 12.7 (lbs devided by hp). If you knock off 100 lbs and assume the same lbs per hp the gain is 7.9 hp. At least that's what my math works out to and I was not a math major soooo could be wrong.

Tyson Schmidt · 01-20-2006, 04:55 PM

Quote:

Originally posted by JohnJL
Wow, 110-115...bad news to be running AC on an aircooled engine in that eat if you get caught in traffic!

Not true on the '90 and newer cars. The condensor is in the left front fender well, and the oil cooler is in the right. There is ne engine decklid condensor. So there is no extra heat added to the engine or oil cooler.

BTW, the A/C weight penalty is closer to 40# for the 964/993.

The compressor weighs 14#, and the rest is from the condensor and fan and the evaporator core. The lines are aluminum, and the evaporator is integral with the HVAC. It's a much lighter/simpler system.

Also the majority of the weight from the A/C is in front. The compressor is very light, and the bracket is integral with the engine mount, and is hollow aluminum.

Oh, and it actually works!

jtratza · 01-20-2006, 05:35 PM

Tyson, Do you know if the 993 compressor can be used on a Carrera and also can it be run on R12? Thanks

jwerion · 01-20-2006, 08:33 PM

I was watching some show on speed vision awhile back it was about how lower weight improves performance and they went thru all math BLA BLA and said that a loss of 100#'s is equal to about a 15 HP gain. So a performance improvement equal to an estimated 18 HP increase seems plausible.

aigel · aigel's Garage

Well, Don mentions it already, there is more advantage than just straight line acceleration with a lighter car. It is nice if there is less weight that wants to go straight in a turn.

3000 lbs is your goal? YIKES! What the heck is so heavy on a 993? My SC is 2575 lbs, if I remember right, and that's with hardly any lightening, besides a/c removal. I still have the truck battery, for example.

George